All the cows have horns
A milk tank!
A eunucorn.
An udder failure.
Brovines.
A: He goes into the barn and slips into a nice warm Jersey.
He wasn't in the mooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooood.